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      1 /*---------------------------------------------------------------------------*
      2  *  voicing.c  *
      3  *                                                                           *
      4  *  Copyright 2007, 2008 Nuance Communciations, Inc.                               *
      5  *                                                                           *
      6  *  Licensed under the Apache License, Version 2.0 (the 'License');          *
      7  *  you may not use this file except in compliance with the License.         *
      8  *                                                                           *
      9  *  You may obtain a copy of the License at                                  *
     10  *      http://www.apache.org/licenses/LICENSE-2.0                           *
     11  *                                                                           *
     12  *  Unless required by applicable law or agreed to in writing, software      *
     13  *  distributed under the License is distributed on an 'AS IS' BASIS,        *
     14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
     15  *  See the License for the specific language governing permissions and      *
     16  *  limitations under the License.                                           *
     17  *                                                                           *
     18  *---------------------------------------------------------------------------*/
     19 
     20 
     21 
     22 #include <stdlib.h>
     23 #include <string.h>
     24 #include <math.h>
     25 #include <assert.h>
     26 
     27 #include <limits.h>
     28 #ifndef _RTT
     29 #include <stdio.h>
     30 #endif
     31 
     32 #include "all_defs.h"
     33 #include "voicing.h"
     34 
     35 #include "portable.h"
     36 
     37 #include "../cfront/sh_down.h"
     38 
     39 #define DEBUG        0
     40 
     41 
     42 static const char voicing[] = "$Id: voicing.c,v 1.1.10.5 2007/10/15 18:06:24 dahan Exp $";
     43 
     44 
     45 void init_voicing_analysis(voicing_info *chan)
     46 {
     47   chan->count = -1;
     48   chan->sil_count = 0;
     49   chan->speech_count = 0;
     50   chan->fast_count = 0;
     51 #if DEBUG
     52   log_report("U: 255 255 255 -1 -1 -1 -1\n");
     53 #endif
     54   return;
     55 }
     56 
     57 long voicing_analysis(voicing_info *chan, voicedata enval , int* log)
     58 {
     59   long  retval;
     60   int   threshold;
     61 
     62   if (chan->count < 0)
     63   {
     64     chan->b1 = SHIFT_UP(enval, 8);
     65     chan->b0 = SHIFT_UP(enval, 8);
     66     chan->count = -1;
     67   }
     68 
     69   /*  background level
     70   */
     71   if (chan->b0 > SHIFT_UP(enval, 8))
     72   {
     73     chan->b0 = SHIFT_UP(enval, 8);
     74     chan->count = 0;
     75   }
     76   if (chan->count > B0_HANG2)
     77     chan->b0 += B0_RATE2;
     78   else if (chan->count > B0_HANG1)
     79     chan->b0 += B0_RATE1;
     80 
     81   chan->count++;
     82 
     83   /*  the second background level
     84   */
     85   if ((enval - chan->quiet_margin) < (chan->b0 >> 8))
     86     chan->b1 += SHIFT_DOWN(B1_RATE * (SHIFT_UP(enval, 8) - chan->b1), 8);
     87 
     88   /*  speech level
     89   */
     90   if (chan->s0 < SHIFT_UP(enval, 8))
     91     chan->s0 = SHIFT_UP(enval, 8);
     92   else
     93     chan->s0 -= B0_RATE1;
     94 
     95   /*  increase the range by 25% */
     96   threshold = (chan->b1 + (SHIFT_DOWN(
     97                              MAX(chan->s0 - chan->b0 - DYNAMIC_RANGE, 0), 2))) >> 8;
     98 
     99   /*  Is it speech?
    100   */
    101   if (enval > (threshold + chan->margin))
    102     chan->speech_count++;
    103   else
    104     chan->speech_count = 0;
    105 
    106   /*  Is it Fast-match speech
    107   */
    108   if (enval > (threshold + chan->fast_margin))
    109     chan->fast_count++;
    110   else
    111     chan->fast_count = 0;
    112 
    113   if (enval <= (threshold + chan->quiet_margin))
    114     chan->sil_count++;
    115   else
    116     chan->sil_count = 0;
    117 
    118   /*******************
    119    * Returning flags *
    120    *******************/
    121 
    122   retval = 0L;
    123 
    124   if (chan->fast_count > chan->voice_duration)
    125     retval = FAST_VOICE_BIT;
    126   else if (chan->sil_count > chan->quiet_duration)
    127     retval = QUIET_BIT;
    128 
    129   if (chan->speech_count > chan->voice_duration)
    130     retval |= VOICE_BIT;
    131 
    132   if (chan->sil_count > 0)
    133     retval |= BELOW_THRESHOLD_BIT;
    134 
    135   chan->voice_status = retval;
    136 #if DEBUG
    137   log_report("U: %d %.1f %.1f, %d %d %d %d\n", (int) enval,
    138              chan->b0 / 256.0, chan->b1 / 256.0,
    139              chan->speech_count, chan->fast_count,
    140              chan->sil_count, chan->count);
    141 #endif
    142   return (retval);
    143 }
    144